l10n: command arguments value name is not localized

[lordeji]

I'm new to localization so I tried weblate. When i was improving the translation for "split", I noticed that english value names were mixed with translated value names in the documentation.
For example :

-l, --lines <NUMBER>              mettre NOMBRE lignes/enregistrements par fichier de sortie [default: 1000]
-n, --number <CHUNKS>             générer CHUNKS fichiers de sortie ; voir l'explication ci-dessous

After looking around in the source code the culprit seems to be the Arg::value_name() function.
For example, in uu/split/src/split.rs :

pub fn uu_app() -> Command {
  Command::new(uucore::util_name())
    [...]
    .arg(
      Arg::new(OPT_LINES)
        .short('l')
        .long(OPT_LINES)
        .allow_hyphen_values(true)
        .value_name("NUMBER")
        .default_value("1000")
        .help(translate!("split-help-lines")),
    )
    [...]
}

---

There is two ways to deal with that :

1. If it's voluntary, then it's necessary to write some specification so that the localization does not switch between two languages too much. Does the value name must stay in english or they can be translated while the value name stays in english as usage.
2. Change every value_name() call to something like that

.value_name(translate!("split-help-lines-value-name"))

and update the english locale accordingly.

I would gladly take care of this task but I just need to better understand the code (i'm new to l10n) so i'm not confident if replacing the value name strings with translate!() and updating the en-US.flt files is sufficient/works.

[lordeji]

Here is a small example of changes to make it works (here i'm just modifying uu/split folder).

Add in locales/en-US.ftl :

split-help-number-value-name = CHUNKS

Add in locales/fr-FR.ftl :

split-help-number-value-name = BLOCS

Then in src/split.rs :

.value_name(translate!("split-help-number-value-name"))

But there was an error saying the trait 'From<std::string::String>' is not implemented for 'Str' because the .value_name() function has as argument trait impl IntoResettable<Str> which is different from .help() function which has as argument trait impl IntoResettable<StyledStr>.
After looking around in the documentation, it seems that the string feature is necessary so that struct Str support dynamic values like String.
I just changed the local Cargo.toml file with :

clap = { workspace = true, features = ["string"] }

---

I compiled with :

cargo build -p uu_split
cargo build --release -p uu_split
cargo build
cargo build --release

With no compilation error/warning.
The big problem is that localization does not exist when building in release mode (tested cleaning then building with only split package then multicall bin and both didn't have localization).
At the contrary both the split package and multicall bin supported localization in debug mode.

I don't understand why because the uutils package released on the AUR support localization.

---

When localization is present the output now looks like :

$ LANG=en_US split --help
[...]
-n, --number <CHUNKS>             generate CHUNKS output files; see explanation below
[...]

$ LANG=fr_FR split --help
[...]
-n, --number <BLOCS>              générer CHUNKS fichiers de sortie ; voir l'explication ci-dessous
[...]